Focus on strengthening glutes and ankle stability. Make sure that there is no pain in your knee carrying out these exercises. If there is pain you can find straight leg alternatives.
Glute bridge, one leg deadlift, Bulgarian squat, Curtsy squat - perform with weights to increase difficulty. Also Clamshell, Donkey kick, fire hydrant for glutes specifically.
If you go to a pilates class the teacher would provide a good variation of all of these exercises with some good core strengthening.